What is the purpose of a transformer?

A transformer is a device designed primarily to change the voltage of alternating current (AC) in a circuit. Its main function is to either increase (step-up transformer) or decrease (step-down transformer) the voltage levels as needed for different applications. By adjusting these voltage levels, transformers enable the efficient transmission of electricity over long distances and also allow electrical devices to operate safely at the required voltage levels.

For instance, in power distribution, high voltages are used for transmission to minimize energy loss over distances. When the electricity reaches its destination, transformers reduce the voltage to a safer level for consumer use. Thus, the purpose of a transformer is fundamentally linked to its ability to modify voltage levels, which is critical for the efficient distribution and utilization of electrical energy. This functionality distinguishes it from devices that store energy, regulate environmental conditions, or measure electrical resistance, which serve entirely different roles in electrical systems.